mercurial-core: update Rust nightly version

This is quite outdated, let's use a newer one. No changes to the formatting
have ensued from this upgrade.
29 jobs for topic/default/rust-version in 16 minutes and 36 seconds (queued for 7 seconds)
latest
Status Job ID Name Coverage
  Check
passed shellcheck #244803

00:00:13

 
  Image Build 0
passed build:base #244804

00:03:05

 
  Image Build 1
passed build:mercurial-core #244805

00:07:52

passed build:py2-hgext3rd #244806

00:02:15

passed build:py3-hgext3rd #244807

00:01:37

 
  Image Build 2
passed build:mercurial-core-fb-re2 #244809

00:03:22

passed build:mercurial-core-pyre2 #244808

00:05:25

passed build:py2-hgext3rd-hg-x.y: [4.3] #244810

00:03:17

passed build:py2-hgext3rd-hg-x.y: [4.4] #244811

00:04:00

passed build:py2-hgext3rd-hg-x.y: [4.5] #244812

00:03:19

passed build:py2-hgext3rd-hg-x.y: [4.6] #244813

00:03:23

passed build:py2-hgext3rd-hg-x.y: [4.7] #244814

00:03:44

passed build:py2-hgext3rd-hg-x.y: [4.8] #244815

00:03:56

passed build:py2-hgext3rd-hg-x.y: [4.9] #244816

00:04:17

passed build:py2-hgext3rd-hg-x.y: [5.0] #244817

00:03:28

passed build:py2-hgext3rd-hg-x.y: [5.1] #244818

00:04:16

passed build:py2-hgext3rd-hg-x.y: [5.2] #244819

00:03:40

passed build:py2-hgext3rd-hg-x.y: [5.3] #244820

00:02:18

passed build:py2-hgext3rd-hg-x.y: [5.4] #244821

00:01:50

passed build:py2-hgext3rd-hg-x.y: [5.5] #244822

00:02:02

passed build:py2-hgext3rd-hg-x.y: [5.6] #244823

00:01:50

passed build:py2-hgext3rd-hg-x.y: [5.7] #244824

00:02:18

passed build:py2-hgext3rd-hg-x.y: [5.8] #244825

00:01:54

passed build:py3-hgext3rd-hg-x.y: [5.3] #244826

00:03:27

passed build:py3-hgext3rd-hg-x.y: [5.4] #244827

00:01:44

passed build:py3-hgext3rd-hg-x.y: [5.5] #244828

00:03:22

passed build:py3-hgext3rd-hg-x.y: [5.6] #244829

00:01:44

passed build:py3-hgext3rd-hg-x.y: [5.7] #244830

00:03:01

passed build:py3-hgext3rd-hg-x.y: [5.8] #244831

00:03:37